This invention relates to evaporative coolers and more particularly to portable coolers designed for use in a motor vehicle, travel trailer or other movable structures. Heretofore most portable evaporative coolers have consisted of a housing enclosing a water sump, evaporative pads contained in respective pad frames upstanding from the sump and a spreader above the evaporative pads arranged to distribute water over the upper edges of the pads to percolate downwardly and return to the sump for recirculation. At the same time air is drawn inwardly through the wetted evaporative pads by a blower, evaporating some of the water and cooling the air which is blown outwardly from the cooler.
Evaporative coolers of this type that are mounted inside the space to b cooled have not provided for outside, non-saturated air, for the intake side of the evaporator pads thereby increasing the humidity of the space to the point of saturation and preventing continued evaporation and cooling by the apparatus. Moreover, such coolers are unable to prevent water contained in the sump from spilling or splashing out through the evaporative pads when the vehicle is in motion or in an unlevel position.